A couple of years ago, I did an article about some of the catchy jingles that represented the various superstores in Akihabara including the one that I focused on, the kiddieland-friendly "Hello, Sofmap World".
Well, although I did mention the massive Yodobashi Akiba, I never got around to its theme song. Incidentally, before I go ahead with that song, I have to say that since the building was erected, it was the place for me to take friends from Toronto whenever they visited during my life there. Even when I visit Japan as a mere tourist now, I still make sure that I drop by the place just to take a look around at the goods and also to visit one of the many restaurants on the higher floor. I'm not exaggerating too much when I say that a visitor wanting to explore all that Akihabara has to offer can easily spend an entire day in this Yodobashi branch. It would basically be one day for Yodobashi Akiba and then another day for the rest of Akiba.
As I cited above, the jingle for Sofmap is a tune that would have folks envision a fantasy land for kids. The one for Yodobashi Camera is jazzier...and familiar, especially for Americans. Yup, once you hear it, you'll know it's completely based on "Battle Hymn of the Republic" by William Steffe and Julia Ward Howe from the mid-19th century.
According to the J-Wiki article, the initial version had been just an instrumental march with some male chorus in the background, but then in 1986, the singer Poplar（ポプラ）, who has focused on theme songs for anime and dramas as well as commercial jingles, gave a slightly rock version of "Yodobashi Camera no Uta" (The Yodobashi Camera Song).
But then in 1990, anison singer and vocal trainer MIQ (pronounced Miku) performed the jazzier take that has been usually heard in the stores nowadays. I tried to find out who came up with the Japanese lyrics but apparently they differ depending on the branch whether it is in Tokyo, Osaka or Sapporo, for example. So I can only figure that someone in an advertising company or the marketing division of Yodobashi itself has been responsible for those. However, the lyrics for the branch in Shinjuku West were created by the actual founder, Terukazu Fujisawa（藤沢昭和）.
The above video is approaching three years old and so the format has changed since then (according to my visit there last year), but you can take a gander at the restaurant floor for Yodobashi Akiba. I don't have any recommendations; they all seem scrumptious!